1. Field of the Invention
The present invention relates to a CAD system.
2. Description of the Related Art
The design of thermal, nuclear or hydroelectric power plants involves planning the layout of the various piping systems used in the respective plants. In recent years, CAD systems capable of three-dimensional layout adjustment have been used for this layout planning work, due to the good usability that they offer, from the data input step to the development and management of the layout at subsequent steps in the design procedure of the plant. A three-dimensional layout adjustment CAD system, and the related software, are known as “tools”.
In work relating to layout planning, the piping designer, using a three-dimensional layout adjustment CAD, arranges pipe components in a three-dimensional virtual space to create piping routes, resulting in creating layout data for the pipe components. Furthermore, a database of pipe specifications data is created using attribute information of piping system to be designed in the form of a spreadsheet, or the like.
In this layout data and specification database, numbers of the piping system are essential as keys, and information relating to the components, such as detailed system name, maximum operating pressure and temperature of the piping system, pipe wall thickness, material, grooves for butt welding, and the like, is written to the database. An operation of this kind is carried out in respect of all of the pipe relating to the plant, thereby building up layout data and a specifications database of the three-dimensional layout adjustment CAD.
More specifically, when using recent tools, isometric diagrams are output automatically on the basis of the layout data of the three-dimensional layout adjustment CAD. These diagrams are simple and straightforward, and therefore only contain the minimum necessary level of information relating to installation, however, provided that this information is output, then it is possible to carry out an installation arrangement which is at least problem-free.
A further concern in regard to installation are the “pipe spools”. A “spool” is the smallest installation unit handled at the installation site, and it signifies a unit which is manufactured in a factory before being transported to the installation site. The spools are set to a size which is suitable for manufacture in a factory, transportation from the factory to the site, and installation at the site. Pipe spools of this kind are manufactured in the factory by welding together straight pipe sections, joints, flanges, and weldolets, and these welds are called “shop welds”.
On the other hand, the welding together of respective pipe spools at the installation site is called a “site weld”. With respect to shop welds and site welds, in general, machining and welding is easier to carry out in a factory since appropriate processing equipment can be installed, and therefore priority is given to increasing the number of shop welds. However, if consideration is given to the convenience of processing at the installation site, then there are cases where pipe spools having a simple format are easier to handle. For example, spools formed by simply welding a joint to a straight pipe section using a shop weld may cause an increase in the number of on-site welds required, but they are not liable to create problems due to manufacturing nonconformities in the factory.
Conventionally, in plant design using three-dimensional CAD, technology for defining pipe spools such as those described above has been proposed (see, for example, Japanese Patent Application Publication No. 2000-293567).
However, in the conventional technology described above, all of the isometric diagrams are output from a tool in relation to a plurality of spools of the same format, and therefore the number of diagrams handled in one project becomes very large, and hence the management work increases, resulting in a very large task load.
In other words, if there are a plurality of spools of the same format for a particular plant, then in the conventional technology, all of the isometric diagrams for each of the spools are output from a tool, respectively and separately. As a result, diagrams are produced in the form of one sheet per component, even in the case of spools of the same format, or spools which are only a little different in terms of their dimensions. Consider, for instance, a case of spools having a simple format, where the number of different spools is very large, but the differences between the respective diagrams for each spool only relate to differences in the length of the straight pipe sections. Since these spools cannot be handled collectively, then it is necessary to manage a large volume of diagrams with recognizing those respective differences.
Furthermore, during the design procedure, if the piping layout is changed, then the spool diagrams must also be revised, but carrying out revision work for a huge number of diagrams which have been prepared individually as described above merely serves to make the amount of revision work involved much greater still. Consequently, the number of diagrams handled in one project becomes enormous, and the management work therefore increases, leading to a very large task load.
The present invention was devised in order to resolve the prior art problems such as those described above, an object thereof being to reduce the number of diagrams and the workload relating to their management, and the like, by aggregating spools of a common format, in technology relating to plant design using a three-dimensional CAD.